Hinges are widely used in door frames and door panels. In general, a conventional hinge is used in connecting a door frame and a door panel and opening/shutting a door which is essentially comprised of the door frame and the door panel. To meet human beings' needs further, it is feasible for a conventional hinge to serve a positioning purpose as well, by working in conjunction with a hydraulic positioning mechanism disposed between the door frame and the door panel. However, the hydraulic positioning mechanism that serves the aforesaid positioning purpose is structurally intricate and difficult to install between the door frame and the door panel and uninstall. In case a heavy electronic device, such as a circuit system installed on the lid of an electronic mailbox, is installed on the door panel, the door panel will be unlikely to be well-positioned under the weight of the electronic device, and in consequence the door may shut by itself at any time, thereby posing a threat to user safety.
In attempt to overcome the aforesaid drawbacks of the prior art, Taiwan Patent Nos. M255893 and M331028 were put forth. M255893 proposes effectuating a positioning function by the coordinated operation of a spring and a serrate inner side of a hinge. However, a pin disclosed in M255893 for serving a rotational purpose is riveted to the hinge and thus cannot be removed therefrom. Likewise, a heavy electronic device installed on a door panel of M255893 poses a threat to user safety as described above. The unremovable pin of M255893 renders it difficult to perform maintenance on the electronic device installed on the door panel. M331028 proposes effectuating a positioning function by the coordinated operation of a spring, a positioning ball, and a positioning hole. However, in M331028, removal of the spring and the positioning ball from the positioning hole entails separating a screw and a nut and thus is difficult. In case a heavy electronic device is installed on the door panel of M331028, users will be endangered in the aforesaid manner. For the aforesaid reason, maintenance of the electronic devices applicable to M331028 is seldom easy.
Accordingly, it is imperative to provide a hinge configured to be stably positioned by a simple mechanism and advantageously characterized by ease of installation and uninstallation.